← Back to Patent Explorer
US5401993A Expired / Lapsed US ⏱️ 0.0 years remaining

Non-volatile memory

Assignee: Sharp Corp
•
Filing: 1993-06-30
•
Granted: 1995-03-28
•
Expires: 2013-06-30
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A non-volatile memory includes a single transistor having a semiconductor substrate, source and drain diffusion layers formed on a surface of the semiconductor substrate, and a gate electrode provided on the semiconductor substrate with a gate insulating film interposed between them. The non-volatile memory further includes a programmable insulating film provided in self-alignment between the gate electrode and at least one of the source and drain diffusion layers and the programmable insulating film is broken down by a voltage applied to the gate electrode so as to execute programming.

Inventors

  • 👤 Yoshimitsu Yamauchi
  • 👤 Kenichi Tanaka
  • 👤 Keizo Sakiyama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 22:20
CPC Classifications
G; G11; G11C; G11C17/00; G11C17/14; G11C17/16; H; H10; H10B; H10B20/00; H10B69/00

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 161 words
A non-volatile memory cell of which includes a single MOS transistor, comprising: a semiconductor substrate; source and drain diffusion layers and a channel region between said source and diffusion layers formed on a surface of said semiconductor substrate; a gate electrode disposed over said semiconductor substrate with a gate insulating film interposed between said gate electrode and said channel region; and a programmable insulating film provided in self-alignment between said gate electrode and either one of said source and drain diffusion layers so that said programmable insulating film is selectively broken down by a predetermined voltage applied to said gate electrode to execute programming and electrically conduct between said gate electrode and either one of said source and drain diffusion layers, and a breakdown voltage of said gate insulating film is higher than that of said programmable insulating film and said predetermined voltage; said gate insulating film and said programmable insulating film disposed adjacent to each other under said gate electrode.
Claim 2
Dependent Claim 161 words
A non-volatile memory cell of which includes a single MOS transistor, comprising: a semiconductor substrate; source and drain diffusion layers and a channel region between said source and diffusion layers formed on a surface of said semiconductor substrate; a gate electrode disposed over said semiconductor substrate with a gate insulating film interposed between said gate electrode and said channel region; and a programmable insulating film provided in self-alignment between said gate electrode and either one of said source and drain diffusion layers so that said programmable insulating film is selectively broken down by a predetermined voltage applied to said gate electrode to execute programming and electrically conduct between said gate electrode and either one of said source and drain diffusion layers, and a breakdown voltage of said gate insulating film is higher than that of said programmable insulating film and said predetermined voltage; said gate insulating film and said programmable insulating film disposed adjacent to each other under said gate electrode.
Claim 3
Dependent Claim 45 words
A non-volatile memory cell according to claim 1, wherein said gate insulating film comprises an SiO 2 film and said programmable insulating film comprising an Si x N 1-x film (0<X<1) which requires a smaller charge for being broken down than said SiO 2 film.
Claim 4
Dependent Claim 41 words
A non-volatile memory according to claim 1, wherein said programmable insulating film is provided on an upper surface of said gate electrode and on side walls of said gate electrode including either one of said source and drain diffusion layer regions.
Claim 5
Dependent Claim 24 words
A non-volatile memory according to claim 1, wherein said programmable insulating film is provided in self-alignment between said gate electrode and said diffusion layer.
Claim 6
Dependent Claim 35 words
A non-volatile memory cell according to claim 1, wherein either said source or drain diffusion layer is grounded at a side free from the formation of said programmable insulating film at the time of programming.
Claim 7
Dependent Claim 171 words
A non-volatile memory cell of which includes a single MOS transistor, comprising: a semiconductor substrate; source and drain diffusion layers and a channel region between said source and drain diffusion layers formed on a surface of said semiconductor substrate; a gate electrode disposed over said semiconductor substrate with a gate insulating film interposed between said gate electrode and said channel region; and a programmable insulating film provided in self-alignment between said gate electrode and either one of said source and drain diffusion layers and between said gate electrode and a polysilicon spacer in ohmic contact with at least one of said source and drain diffusion layers and on a side wall of said gate electrode so that said programmable insulating film is selectively broken down by a voltage applied to said gate electrode to execute programming and electrically conduct between said gate electrode and either one of said source and drain diffusion layers, and a breakdown voltage of said programmable insulating film is smaller than that of said gate insulating film.
Claim 8
Dependent Claim 171 words
A non-volatile memory cell of which includes a single MOS transistor, comprising: a semiconductor substrate; source and drain diffusion layers and a channel region between said source and drain diffusion layers formed on a surface of said semiconductor substrate; a gate electrode disposed over said semiconductor substrate with a gate insulating film interposed between said gate electrode and said channel region; and a programmable insulating film provided in self-alignment between said gate electrode and either one of said source and drain diffusion layers and between said gate electrode and a polysilicon spacer in ohmic contact with at least one of said source and drain diffusion layers and on a side wall of said gate electrode so that said programmable insulating film is selectively broken down by a voltage applied to said gate electrode to execute programming and electrically conduct between said gate electrode and either one of said source and drain diffusion layers, and a breakdown voltage of said programmable insulating film is smaller than that of said gate insulating film.
Claim 9
Dependent Claim 45 words
A non-volatile memory cell according to claim 6, wherein said gate insulating film comprises an SiO 2 film and said programmable insulating film comprising an Si x N 1-x film (0<X<1) which requires a smaller charge for being broken down than said SiO 2 film.
Claim 10
Dependent Claim 35 words
A non-volatile memory cell according to claim 6, wherein either said source or drain diffusion layer is grounded at a side free from the formation of said programmable insulating film at the time of programming.

References Cited (Backward Citations)

JPS57111855A Cited
US4491857A Cited
US4507756A Cited
US4507757A Cited
JPS6184868A Cited
US4823181A Cited
JPS63224355A Cited
US4878100A Cited
US4906587A Cited
US5060034A Cited
US5049957A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-03-27 1998-09-26 1999-03-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-03-27 2002-09-26 2003-03-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-03-27 2006-09-26 2007-03-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag